Radioactive dating gcse questions
With paper, or plastic, or aluminium foil, b rays are used, because a will not go through the paper.
The type of radiation they emit and the half-life are the two things that help us decide what jobs a substance will be best for.Smoke alarms contain a weak source made of Americium-241.Alpha particles are emitted from here, which ionise the air, so that the air conducts electricity and a small current flows.Radioactive substances will give out radiation all the time, regardless of what happens to them physically or chemically.As they decay the atoms change to daughter atoms, until eventually there won't be any of the original atoms left.If smoke enters the alarm, this absorbs the a particles, the current reduces, and the alarm sounds. In paper mills, the thickness of the paper can be controlled by measuring how much beta radiation passes through the paper to a Geiger counter.
The counter controls the pressure of the rollers to give the correct thickness.
Radioisotopes can be used for medical purposes, such as checking for a blocked kidney.
To do this a small amount of Iodine-123 is injected into the patient, after 5 minutes 2 Geiger counters are placed over the kidneys.
The age of the ancient organic materials can be found by measuring the amount of Carbon-14 that is left.
The most common tracer is called Technetium-99 and is very safe because it only emits gamma rays and doesn't cause much ionisation.
Easily modified for different abilities, with my low ability I made all the percentages either 75%, 50% or 25% to make it much easier for them. The worksheets can be used in a number of ways, I used them in two ways, I laminated them both in the same pouch front to back for them to use as a mini whiteboard and write directly on them with a whiteboard pen then rub out the ink for reuse for different questions and classes and to use as group work.